I recently bought a Torker Cargo T bike and it has a huge front rack and a heavy duty rear rack. I am going to either fabricate some rectangular rear cargo boxes out of diamond plate aluminum, 1/8 inch flat stock or buy a pair of heavy duty plastic tool boxes and attach J-Hooks to hang them from the rack with a lower attached bungee cord to secure them. My problem with many of the rear factory cargo Bike baskets is they aren't big enough or configured correctly for carrying certain items like Square boxes. Case in point, I have the Largest Set of Wald Baskets #535 (like 18x13x7) on my old Beater but the problem is they are tapered from Top to bottom. The problem is if you are carrying a Gallon of Milk or paint, the basket at the bottom is too narrow to allow you to put it all the way down in the basket securely. That's an otherwise fine rack for the money. In my checking out a few toolbox websites, as well as Amazon.com, I have found a couple of Tool boxes that would suit my needs. Klein is one, Sears is another place. They are Rectangular and have a hinged or detachable Lid and are approx 18" long, 12 inches high and approx 8 inches wide. And they add little to the weight. They retail from around $19- $30 and it would be easy to attach a hasp to lock and secure the contents. Not to forget, they come in Bright Orange or Safety Yellow color schemes with a black Lid. That's my low cost solution

My Recent purchase:http://1.bp.blogspot.com/_G1N4SIcd-j...-h/Cargo_T.jpg